1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
//! Function sites, compared within their module.
use alloc::format;
use alloc::string::{String, ToString};
use alloc::vec::Vec;
use syn::spanned::Spanned;
use crate::cfg::cfgs;
use crate::{DocTest, Remedy, SourceFile};
/// One function as found in a source file.
pub(crate) struct FnSite {
/// The reported site.
pub(crate) site: DocTest,
/// The declaration's finished canonical form in its original context.
pub(crate) form: syn_canon::CanonicalForm,
/// The original scope and what decides whether a copy can be deleted.
pub(crate) context: Context,
}
/// The original scope, where a function is defined, whether it exports a symbol, and under
/// which `cfg`, the last two of which the comparison ignores.
#[derive(Debug, Clone, PartialEq, Eq)]
pub(crate) struct Context {
/// The crate root file and module path, part of the local hash and the organization
/// owner identity.
pub(crate) scope: String,
owner: Owner,
exported: bool,
/// The printed `cfg` attributes, sorted, since their order carries no meaning.
cfg: Vec<String>,
}
/// What holds a function.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum Owner {
/// A module.
Free,
/// An inherent impl.
Inherent,
/// A trait impl or a trait's default methods.
Trait,
}
/// The remedy of a group's copies, from the first matching row of the table in the spec.
pub(crate) fn remedy(sites: &[(DocTest, Context)]) -> Remedy {
let Some(((first, first_context), rest)) = sites.split_first() else {
return Remedy::Delete;
};
if rest
.iter()
.any(|(site, _)| site.self_type != first.self_type)
{
Remedy::GenericOrMacro
} else if sites
.iter()
.any(|(_, context)| context.owner == Owner::Trait || context.exported)
{
Remedy::HelperOrMacro
} else if rest
.iter()
.any(|(_, context)| context.cfg != first_context.cfg)
{
Remedy::MergeCfg
} else {
Remedy::Delete
}
}
/// Cross-scope copies require extraction or generic sharing.
pub(crate) fn remedy_organization(sites: &[(DocTest, Context)]) -> Remedy {
match sites.split_first() {
Some(((first, first_context), rest))
if rest
.iter()
.any(|(_, context)| context.scope != first_context.scope) =>
{
if first.self_type.is_some()
&& rest
.iter()
.any(|(site, _)| site.self_type != first.self_type)
{
Remedy::GenericOrMacro
} else {
Remedy::HelperOrMacro
}
}
_ => remedy(sites),
}
}
/// The free functions, impl methods and trait default methods of `file`, nested functions
/// excluded, each declaration canonicalized in `context`.
pub(crate) fn functions(
prefix: &str,
file: &SourceFile,
root: &str,
crate_root: &str,
library: bool,
context: &syn_canon::SourceContext<'_>,
) -> Vec<FnSite> {
let path = file
.path
.strip_prefix(root)
.and_then(|p| p.strip_prefix('/'))
.unwrap_or(&file.path);
let lines: Vec<&str> = file.text.lines().collect();
let mut walk = Walk {
path,
crate_root,
library,
lines: &lines,
cfg: file.cfg.clone(),
context,
out: Vec::new(),
};
walk.items(&file.parsed.items, prefix);
walk.out
}
/// The walk over one source file.
struct Walk<'a> {
path: &'a str,
crate_root: &'a str,
/// Whether the file belongs to a library, whose `pub` functions are public API.
library: bool,
lines: &'a [&'a str],
/// The `cfg` attributes of the module declarations, inline modules, impls and traits the
/// walk is inside.
cfg: Vec<String>,
context: &'a syn_canon::SourceContext<'a>,
out: Vec<FnSite>,
}
impl Walk<'_> {
fn items(&mut self, items: &[syn::Item], module: &str) {
for item in items {
match item {
syn::Item::Fn(f) => {
self.push(
module,
None,
f,
Parts {
attrs: &f.attrs,
vis: &f.vis,
sig: &f.sig,
block: &f.block,
},
);
}
syn::Item::Mod(m) => {
if let Some((_, inner)) = &m.content {
let depth = self.enter(&m.attrs);
self.items(inner, &format!("{module}::{}", m.ident));
self.cfg.truncate(depth);
}
}
syn::Item::Impl(i) => {
let self_type = type_text(&i.self_ty);
let owner = if i.trait_.is_some() {
Owner::Trait
} else {
Owner::Inherent
};
let depth = self.enter(&i.attrs);
for member in &i.items {
if let syn::ImplItem::Fn(f) = member {
self.push(
module,
Some((&self_type, owner)),
f,
Parts {
attrs: &f.attrs,
vis: &f.vis,
sig: &f.sig,
block: &f.block,
},
);
}
}
self.cfg.truncate(depth);
}
syn::Item::Trait(t) => {
let self_type = t.ident.to_string();
let inherited = syn::Visibility::Inherited;
let depth = self.enter(&t.attrs);
for member in &t.items {
if let syn::TraitItem::Fn(f) = member
&& let Some(block) = &f.default
{
self.push(
module,
Some((&self_type, Owner::Trait)),
f,
Parts {
attrs: &f.attrs,
vis: &inherited,
sig: &f.sig,
block,
},
);
}
}
self.cfg.truncate(depth);
}
_ => {}
}
}
}
/// Push the `cfg` attributes of an item the walk enters, returning the depth to restore.
fn enter(&mut self, attrs: &[syn::Attribute]) -> usize {
let depth = self.cfg.len();
self.cfg.extend(cfgs(attrs));
depth
}
/// Record the function `whole`, attributes and doc comments included, `method` holding
/// the self type and owner of a method.
fn push(
&mut self,
module: &str,
method: Option<(&str, Owner)>,
whole: &impl Spanned,
parts: Parts<'_>,
) {
let Parts {
attrs,
vis,
sig,
block,
} = parts;
let (self_type, owner) = match method {
Some((self_type, owner)) => (Some(self_type), owner),
None => (None, Owner::Free),
};
let span = whole.span();
let (line, end) = (span.start().line, span.end().line);
let allow = line
.checked_sub(2)
.and_then(|above| self.lines.get(above))
.is_some_and(|above| above.trim() == "// echoes: allow");
let item = match self_type {
Some(ty) => format!("{module}::{ty}::{}", sig.ident),
None => format!("{module}::{}", sig.ident),
};
let mut cfg = self.cfg.clone();
cfg.extend(cfgs(attrs));
cfg.sort_unstable();
let code = self
.lines
.get(line.saturating_sub(1)..end.min(self.lines.len()))
.unwrap_or_default()
.join("\n");
let scope = format!("{}\n{module}", self.crate_root);
self.out.push(FnSite {
site: DocTest {
file: self.path.to_string(),
line: u32::try_from(line).unwrap_or(u32::MAX),
end: u32::try_from(end).ok(),
item,
info: Vec::new(),
code,
allow,
self_type: self_type.map(ToString::to_string),
public: self.library && matches!(vis, syn::Visibility::Public(_)),
},
form: self
.context
.function(sig, block)
.expect("the site's declaration is indexed in the source context")
.canonicalize(),
context: Context {
scope,
owner,
exported: attrs.iter().any(|a| exports(&a.meta)),
cfg,
},
});
}
}
/// The pieces of a function the walk records.
#[derive(Clone, Copy)]
struct Parts<'a> {
attrs: &'a [syn::Attribute],
vis: &'a syn::Visibility,
sig: &'a syn::Signature,
block: &'a syn::Block,
}
/// Whether `meta` exports a symbol, which the symbol's users then need.
fn exports(meta: &syn::Meta) -> bool {
let path = meta.path();
if path.is_ident("unsafe") {
return syn_canon::wrapped(meta, 0).is_some_and(|metas| metas.iter().any(exports));
}
path.is_ident("no_mangle") || path.is_ident("export_name")
}
/// The whole type as written, `Foo<u8>` and `a::Foo` telling apart types one last segment would merge.
fn type_text(ty: &syn::Type) -> String {
let printed = quote::ToTokens::to_token_stream(ty).to_string();
let word = |c: Option<char>| c.is_some_and(|c| c.is_alphanumeric() || c == '_');
let mut out = String::with_capacity(printed.len());
let mut chars = printed.chars().peekable();
while let Some(c) = chars.next() {
if c != ' ' || (word(out.chars().last()) && word(chars.peek().copied())) {
out.push(c);
}
}
out
}